Knurling tool

ABSTRACT

A knurling tool comprising a tool head ( 1 ) which carries at least one knurling wheel ( 2 ) and which is mounted adjustably on a shaft ( 3 ), wherein the tool head ( 1 ) is mounted on the shaft ( 3 ) linearly displaceably transversely with respect to the axis ( 3   a ) of the shaft, characterised in that there is provided a fixing device for securing the relative position of the tool head ( 1 ) and the shaft ( 3 ), the fixing device being arranged between the tool head ( 1 ) and the shaft ( 3 ).

DESCRIPTION

[0001] The invention concerns a knurling tool comprising a tool head which carries at least one knurling wheel and which is mounted adjustably on a shaft, wherein the tool head is mounted on the shaft linearly displaceably transversely with respect to the axis of the shaft.

[0002] Knurling tools comprising a tool head which is mounted adjustably on a shaft are already known. One example is illustrated in German patent DE 970 092. In the state of the art the tool head of the knurling tool is mounted on the shaft rotatably about an axis so that the tool head can be oriented relative to the workpiece to be worked upon, with the shaft being clamped for example to the support of a turning lathe or a CNC-machine.

[0003] A knurling tool in which the tool head is displaceable on the shaft linearly transversely with respect to the axis of the shaft is disclosed for example in U.S. Pat. No. 5,992,199. The tool head is compressed by a clamping screw in order to fix the tool head in position on the shaft.

[0004] It has been found that this adjustment option for the tool head with respect to the shaft is in practice not sufficient to permit adaptation to all types of machine. Rather, it was necessary to manufacture knurling tools of the specified kind, with various shafts, in order to cover the clamping situation in relation to the most common types of machine. In addition, when high loadings are involved, the requirements for adequate stability in respect of shape of the shaft and the tool head are only partially met.

[0005] The object of the invention is to provide a knurling tool of the kind set forth in the opening part of this specification, which, being of a robust structure, can be adjusted in such a way that it can be used in relation to the most widely varying types of machine (for example in the case of machines which rotate clockwise and counter-clockwise) and which in addition enjoys improved stability in respect of shape.

[0006] In accordance with the invention that is attained in that there is provided a fixing device for securing the relative position of the tool head and the shaft, the fixing device being arranged between the tool head and the shaft.

[0007] In that way the tool head call be optimally fixed in its relative position with respect to the shaft without the tool head or the shaft having to be compressed by a clamping device. Therefore—without the provision of a clamping gap—the two structural components can be of a more robust construction, thereby affording improved stability in respect of shape of the knurling tool.

[0008] Particularly precise guidance is possible by means of a dovetail guide means.

[0009] In order to be able to adjust the relative position between the tool head and the shaft, there is provided an adjusting device, for example with an adjusting screw. The set position can then be preferably secured by a fixing device, for example by means of clamping eccentrics.

[0010] Further advantages and details of the invention are described more precisely with reference to the specific description hereinafter.

[0011]FIG. 1 shows a side view of an embodiment of a knurling (milling) tool according to the invention,

[0012]FIG. 2 shows a view in section taken along line A-A in FIG. 1,

[0013]FIG. 3 shows a view in section taken along line B-B in FIG. 2,

[0014]FIG. 4 shows a view in section taken along line C-C in FIG. 3, and

[0015]FIG. 5 shows a perspective view.

[0016] The knurling milling tool shown in FIGS. 1 through 5 has a tool head 1 carrying two knurling wheels 2. As will be described in greater detail hereinafter the tool head 1 is mounted adjustably on the shaft 3.

[0017] Each of the two knurling wheels 2 is mounted freely rotatably about an axis 4 on a pivot pin 6 which in turn is mounted rotatably in the tool head 1. The two pivot pins 6 can be adjusted by way of a screwthreaded spindle 7 jointly but in opposite relationship in the tool head 1, whereby the relative spacing of the two knurling wheels 2 is adjustable. That ‘synchronous adjustment’ is known per se for example from DE 970 092.

[0018] An arresting device 11 is provided in order to secure the rotary position, once set, of the pivot pins 6 about the axis 5 in the tool head 1. The arresting device 11 has a clamping member 12 which on the one hand is supported against an inclined surface 13 of the tool head 1 and which on the other hand bears against the peripheral surface of the pivot pins 6. That clamping member 12 is moved or clamped by way of a screw 14 which can be screwed into the tool head 1. When the screw 14 (with screw head 14 a) is screwed in, in the horizontal direction as shown in FIGS. 1 through 4, the clamping member 12 moves upwardly due to the inclined surface 13 and in a simple manner jointly and synchronously clamps the two pivot pins 6 firmly in the position previously set by way of the spindle screw 7.

[0019] When the screw 14 is unscrewed the disk 9 which is mounted in the groove 8 in the screw 14 and which bears against the rear side 10 of the clamping member 12 entrains the clamping member 12 outwardly and thus actively releases the clamping action.

[0020] To guide the tool head 1 with respect to the shaft 3, the arrangement has a linear guide means 15 which extends transversely with respect to the axis 3 a of the shaft and which in the illustrated embodiment by way of example is in the form of a dovetail guide means.

[0021] Provided as an adjusting device for setting the relative position of the tool head 1 and the shaft 3 is an adjusting screw 16 which extends in the horizontal direction in FIGS. 1 through 4. The adjusting screw 16 is mounted in the shaft 3 rotatably but axially immovably and engages with its screwthread flights 16 a into corresponding screwthread flights 1 a on the tool head 1. That permits precise adjustment of the tool head 1 with respect to the shaft 3. In order to permit play-free movement of the screwthread flights 16 a of the adjusting screw 16 in the screwthread flights 1 a of the tool head 1, the arrangement has a prestressing device which is generally identified by 17 and which urges the adjusting screw 16 into the screwthread flights 1 a on the tool head 1. The prestressing device 17 has a spring 17 a and a pushrod 17 b.

[0022] After the relative position of the tool head 1 with respect to the shaft 3 has been set by way of the adjusting screw 16, that set position can be robustly secured by way of a fixing device. In the present embodiment the fixing device comprises two substantially roller-shaped clamping eccentrics 18 which each extend in the adjustment direction on both sides of the adjusting screw 16. By rotating the clamping eccentrics 18, they are caused to bear snugly and firmly against the tool head 1 and thus provide for clamping the tool head 1 and the shaft 3.

[0023] All in all the relative position of the shaft 3 with respect to the tool head 1 can be quickly and precisely fixed in a simple manner by way of adjustment of the adjusting screw 16 and subsequent rotation of the clamping eccentrics 18. That permits adaptation to the most widely varying types of machine.

[0024] It will be appreciated that the invention is not limited to the illustrated embodiments. For example the tool head 1 may also have a different number of knurling wheels 2. The adjustment and the arrangement of the knurling wheels 2 in the head may also vary. It will be appreciated that the knurling wheels 2 are preferably interchangeable and can be exchanged according to the respective desired knurling effect. 

1. A knurling tool comprising a tool head which carries at least one knurling wheel and which is mounted adjustably on a shaft, wherein the tool head is mounted on the shaft linearly displaceably transversely with respect to the axis of the shaft, wherein there is provided a fixing device for securing the relative position of the tool head and the shaft, the fixing device being arranged between the tool head and the shaft.
 2. A knurling tool as set forth in claim 1 wherein the fixing device has at least one clamping eccentric operative between the tool head and the shaft.
 3. A knurling tool as set forth in claim 2 wherein arranged on each of the two sides of the adjusting device is a respective clamping eccentric extending in the adjusting direction.
 4. A knurling tool as set forth in claim 1 wherein a dovetail guide means is provided for linear guidance of the tool head on the shaft.
 5. A knurling tool as set forth in claim 1 wherein an adjusting device is provided for setting the relative position of the tool head and the shaft.
 6. A knurling tool as set forth in claim 5 wherein the adjusting device has an adjusting screw extending in the adjustment direction.
 7. A knurling tool as set forth in claim 6 wherein the adjusting screw is mounted rotatably but axially immovably in the shaft or the tool head and engages with its screwthread flights into corresponding screwthread flights on the tool head or the shaft respectively.
 8. A knurling tool as set forth in claim 6 wherein a prestressing device is provided for pressing the adjusting screw into the screwthread flights on the tool head or the shaft respectively.
 9. A knurling tool as set forth in claim 1 wherein two knurling wheels are mounted adjustably on the tool head.
 10. A knurling tool as set forth in claim 9 wherein mounted rotatably and adjustably in the tool head is at least one pivot pin which extends transversely with respect to the axis of the shaft and on which a knurling wheel is mounted freely rotatably about an axis extending inclinedly with respect to the axis of the pivot pin.
 11. A knurling tool as set forth in claim 10 characterised in that the axis of the pivot pin or pins is perpendicular to the adjusting direction between the tool head and the shaft. 